While smoking cessation leads to significant improvements in mortality and morbidity, weight gain post- cessation partially attenuates this benefit. Furthermore, concerns about postcessation weight gain are common and are often cited as a reason to delay cessation attempts. In addition, postcessation weight gain is associated with smoking relapse. Thus, although the health benefits of smoking cessation outweigh the negative impact of weight gain, ideally there would be intervention ?packages? that would not require that people choose between smoking cessation and nontrivial weight gain. Thus, in the proposed study, we will determine whether two very promising methods of reducing postcessation weight gain, namely a weight stability intervention (based on the evidence-based Stability Skills First intervention) versus a weight loss intervention (based on the evidence-based Look AHEAD intensive lifestyle intervention) followed by a smoking cessation intervention are efficacious for reducing postcessation weight gain. We will randomize 400 smokers to one of three arms: a) a weight stability intervention prior to cessation (STABLE); b) a weight loss intervention prior to cessation (LOSS), or c) a bibliotherapy comparison condition prior to cessation (BIBLIO) and to determine the efficacy of the interventions on preventing weight gain at 12 month follow-up. All three conditions receive a highly efficacious in-person smoking cessation behavioral intervention and six months of Varenicline (ChantixTM) pharmacotherapy. Those participants randomized to the STABLE and LOSS conditions will receive monthly booster weight management sessions, after completing the behavioral smoking cessation intervention. The primary outcomes will be weight change and smoking cessation at 12 month follow-up. In addition, we will gather process data on mediators of treatment outcome via measures of treatment engagement (e.g., session attendance, varenicline utilization). We will be able to determine whether a weight stability intervention or a weight loss intervention is efficacious in reducing post-cessation weight gain. The intervention results, if successful, could be disseminated and make a significant contribution towards curtailing obesity in this vulnerable population.